RESERVE FOR LOSSES AND LOSS EXPENSES - Narrative (Details)	12 Months Ended
	Dec. 31, 2021	Aug. 05, 2019	Mar. 20, 2017	Mar. 19, 2017
Minimum
Claims Development [Line Items]
Development for an accident year or underwriting year, recognition period	1 year
Maximum
Claims Development [Line Items]
Development for an accident year or underwriting year, recognition period	3 years
Motor Reserve Class | Reinsurance
Claims Development [Line Items]
Discount rate		(0.25%)	(0.75%)	2.50%